New Jersey will be losing hundreds of jobs as three big employers have told the state they are laying off workers and moving some operations elsewhere.

International Technidyne Corp., a medical device manufacturer headquartered in Piscataway, is relocating to San Diego as part of its recent acquisition of Accumetrics, a company based in the city that makes blood-clot monitors. The move will impact 357 jobs in the Garden State, according to a notice the privately held company filed with the state Department of Labor and Workforce Development.

Kim Ballard, vice president of human resources, said the company will be conducting the layoffs on a rolling basis over the next year, and that it intends to make the process as transparent as possible. So far, just under 20 people have been given a 60-day notice that their jobs are being eliminated, she said.

Ballard added the company will be evaluating requests from current workers who want to move with the company to San Diego. “We would love to keep our top talent,” she said.

The company, which is owned by private equity firm Warburg Pincus and also does business as ITC Nexus Holding Co., was founded in 1969 and has operations in Edison. Ballard said the decision to move did not hinge on incentives offered by the state. “There were many factors that went into it, and it was not an easy decision to make,” she said.

In Clifton, pharmaceutical giant GlaxoSmithKline will shutter its oral care manufacturing plant Thursday and begin phasing out the jobs of 165 employees as part of a planned closure announced in April 2010.

Teresa Caro, a Glaxo spokeswoman, said while production will shut down this week, “the site will continue decommissioning activities until June 30, 2014.”

London-based Glaxo will relocate the Clifton facility to Oak Hill, N.Y., about two hours north. The company said Clifton employees have been offered “job opportunities” at the new location and added that workers “interested in relocating to that site have already moved to their new roles.”

Glaxo’s decision to close its Clifton facility is part of a pharmaceutical industry trend in New Jersey, where 14,000 manufacturing jobs have been eliminated over the last decade. The company, however, is maintaining its research and development facility in Parsippany.

Brian Murray, a spokesman for the state Department of Labor, called it coincidental that the layoff notices were all announced around the same time and said it didn’t indicate any “larger shift in the economy.” In May and June, the state went almost seven weeks without a similar layoff notice from a company, he noted.

New Jersey’s unemployment rate stood at 8.5 percent for August, when the state lost 1,500 jobs, the most recent date available. September’s jobs report for New Jersey has been delayed because of the 16-day federal government shutdown.

The loss of jobs at ITC and Glaxo also may be offset by gains elsewhere. Earlier this month, the Chinese appliance manufacturer Haier unveiled plans to relocate its Americas headquarters from New York to Wayne, bringing in some 500 jobs to the Garden State.

Layoffs also will occur Thursday at the New Providence office of legal information company LexisNexis, where 92 jobs are being eliminated, according to a Labor Department filing.

The losses follow a joint venture between LexisNexis, which runs the Martindale-Hubbell online marketing service for lawyers, and Internet Brands of El Segundo, Calif., which has its own online legal marketing division Nolo. There are no plans to close the New Providence office, LexisNexis said in a statement.